To expand on the aforementioned:
EMS and emergent transport in Atlanta are provided by Grady EMS. Grady is a third service (meaning it is apart from police and fire) that operates as an extension of Grady Memorial Hospital (Level I Trauma Center). They respond to about 110,000 calls annually with a max of 28 units in service during peak times. That may increase with major events/holidays. Not sure. Either way, apart from some major financial woes recently Grady has been a superb service. EMS personnel can attend inservice classes that doctors attend and the sky is the limit in terms of their knowledge base. They've never had to rely on mutual aid (according to Grady) since their establishment more than 100 years ago.

As far as first response IN Atlanta, that is Atlanta Fire Department. The majority of their trucks are ALS response as I recall. They do not transport.

Outside of Atlanta but still inside of Fulton County, things get a little more hairy. Tons of cities, Rural Metro, and maybe a few other services involved.

Ok...so here is a little info. about Metro Atlanta

The following is what I know after working/living in the ATL most of my life:

Fulton County EMS:

-Grady covers the city of Atlanta and does Mutual Aid for Fulton County
-Fulton County relies on Rural Metro
-Private Services in Fulton also include Milton Ambulance, and Central Ambulance (Central does 911 back-ups) for Rural Metro

Cobb County EMS:

-Most of Cobb County is covered by Metro Atlanta EMS (private company)
-Georgia EMS which covers the Kennesaw area
-Puckett EMS which covers the southern part of Cobb County

Cherokee County has its own med units

DeKalb County has its own ALS/BLS units, but uses AMR for BLS calls

Gwinnett County also has its own ambulances and does there own transport.

That is all I can really remember...any other questions just post on here